Ventilator



Patented Apr. 17, 1945 UNITED; STATT vEN'rILA'ronl y l James M. Guthrie,Allison Park, Pa., assigner to Frank R. Kelley, Pittsburgh, P a.

'Application october 13, 1942, seria; No. 461,851

. 2 Claims.

This invention relatesto ventilators, and consists in a ventilator cowlof improved and ,simpliiied construction. ,l l y yThe object ofv thelinvention is toA provide a cowl-in which Ventilating eciency andeconomy in manufacture are obtained in most effective combination. 1 ,yl

Experience in the artA of natural ventilationhas shown thatgreatesteftciency, particularly efciency at low wind velocities, is obtainedwith a cowl of the ejector tube type, illustrated and described inLetters Patent No. 1,639,187, granted August 16, 1927 on theyapplication of Frank R. Kelley. The body of the cowl is formed of sheetmetal, andin structure may be likened to a large stovepipeelbow having aninetyfdegree bend. The openings at the two ends of the elbow-shapedbody provide respectively the inlet and the outlet of the cowl, and thecowl body carries onthe periphery of its outlet end an outwardly flaredflange. In the back wall of the cowl body .an

ejector tube is mounted, such tubeextending in,

ward partway across the `throat of the cowl and being directed towardsthe center of the said cowl outlet. f Y

In service the cowl is Vmounted inthe open atmosphere above the buildingor other structure to be ventilated, with the inlet of the cowl. incommunication'with a Ventilating duct extending upwardly from thebuilding. e ',.Ihe cowl; is*` supported for rotation on a vertical axis,'whereby the outlet of the cowl may be faced in downwind direction, withthe mouth of the ejector tube faced into the Wind. The moving air orwind of the atmosphere mpinges'fupon the cowl, and some of the airstreams throughthefejector'tube, to eiect; in known way and inconjunction with the buoyancy or stack effect of the air within thebuilding the aspiration of lair from; the ventilating duct.

Consideringv vthe structure in greater detail,

the body of the cowl is formed of a pluralityof sections of sheet metal.The sections consist in short cylinders whose endsV are inclined thecylinders being (as viewed from theside) wedge, shape in outline.y Theso-shaped cylindricalsec-` tions are united edge to ed'gein the formlof'an elbow of substantially ninetybdegrees `(90) inv angular extent.Manifestly, lta-"tubular fstructure of this sort is an expensive thingto con v struct, this apart from vany, consideration ofthe cost of theflange that issubsequently vprovided at the outlet of the cowl, `or,thecost of installing that at ywind velocities of higher value there isno difficulty inA obtaining adequate Ventilating effect with any of theless specialized cowls.

In `the accompanying drawingl Figure I is a view of a ventilatorinstallation that affords an exemplary embodiment lof the invention; theventilator cowl is shown partly in side elevation and partly in verticalsection, with the Vane of the cowl and the Ventilating uptake with which1 suing description of the cowl structure.

Figure II'is ay view side elevation and to smaller scale oftheventilator, illustrating certain permissible modications in the cowlstructure.

4 In accordance lwith the invention, the tubular body 2 of the cowl,is-made in the form of a truncated cone, by virtue of whchgit becomespossible to construct-the 4cowl body of a'single piece of sheet metal,cut to appropriate pattern, bent into a conical tube, and the meetingedges united in a single seam.

The inlet of the cowl consists in an orifice 3 that opens through thewall of the conical body 2 from below. Thelarger end of the bodyprovides the outlet or mouth 4 of the cowl, and carries an outwardlyflared peripheral flange 5, preferably a flange that is of greaterextent or breadth at the top of the mouth and of gradually diminishingbreadth towards the bottom. The body of the cowl includes at its smallerend a reentrant portion 6 of frusto-conical form, and such reentrantportion provides the essential ejector tube of the cowl structure.

f In keeping with usual practice the cowl is mounted for rotation upon astationary base 1, the upper portion 'la of the -base extending upwardinto the inlet 3 of the cowl. The base 'l affords Icommunication betweenthe cowl and the t Ventilating duct or passa-ge `8 from which air is toThe cowl is equipped with a vane I3, whereby under the influence of thewind the cowl is maintained in such position that its mouthfaces'indownwind direction, with the ejector tube 6 directed into the wind.

tok

Ther broken lines 20 indicate in outline the cone toy whose contour thecowl body 2 is formed, and

with the larger end of the cowl directed upward. While the smaller ortruncated end of the conical body lies'in a plane approximately normalto 'the' L axis 2| of the cowl, the larger or basal end of the cone liesat an angle of less than 30, here about to the normal base 23 of thecone, wherefore the cowl body at its top is substantially longer than atits bottom. These features oifstructural organization are of notablevalue, in that they minimize the eiIect of throat constriction,`

which term is the name applied to the well-known tendency for the cowlto throttle the stream of air 'flowing through a ninety degree turn(from vertical to horizontal direction) within it.

It will be perceived that the entire cowl body may be formed of fourpieces of sheet metal, one for the conical body 2 of the cowl, one forthe conical ejector tube 6, one for the flange 5, and one for the Vanei3. The arrangement of the ejector tube is particularly to be noted. Theconical body of the tube is arranged with its taper opposite to thetaper of theA conical body 2 of the cowl', and the tube is united at itslarger end to the smaller end of the cowl body, a simple rolled orcrimped joint I6 being effective for the purpose.

In Figure II a cowl of the invention is provided with a cylindricalportion 30, which comprises a skirt around the inlet (3, Figure I) thatopens through the wall of thevcowland overlies the upper edge of thebase portion 1a. By virtue of the skirt 30, the portion la of thebaserneed .not extend upward into the cowl body, as it does inl thestructure of Figure I. In further renement an outwardly flared flange 60is provided on .the smaller end of the cowl body. This ,flange `augmentsthe efliciency of the ejector tube.

In each of the structures of Figures I and II, a counterweight I4 may-be used to balance the cowl with respect to the vertical axis on whichit rotates.

The cowl may be constructed in Various sizes,z

5. Diameter of the truncated Vend offthe cone 6. Angle between base 23of the cone and the mouth 4 of the cowl=15.

7. Length of the reentrant orV ejector tube j portion S of the cowl=10..Y

8. Diameter of the inner -end of tube port-ionv 9. Diameter .of the-inlet 3 in the bottom ofthe' 10. Breadth of the flange 5:5 at the topof the mouth of the cowl, and l" at the bottom.`

1 1. Angle betweenthe outerr or upper surface of the flange 5 and thelouter surface of the` cowl body=155.

l2. Diameter `of the portion la of 'the base-4:v

13. Breadth of the base 1 at the bottom=26".

rsf

14. Height of the base 24".

l5. Angle between axis 2l of the cowl and the horizontal plane passingthrough apex of cone 20=81/.

16. vane shown, to afford suicient wind area and to be of pleasingappearance.

In the structure of Figure II the above dimensions will apply.Additionally, it may be noted that'the `slrirt portion 30 is 17" indiameter, and at the front of the ventilator is of 3" in verticalextent, this affording sufficient data for the pattern maker. The flange6D is 5 in breadth and extends at an angle of to the surface of the cowlbody.

The sheet'metal used in the construction of the ventilator is 24 gageAmerican Standard, and it will be understood that, in constructing cowlswhich are larger or smaller than the one described, sheet metal -ofgreater or less thickness will be used. Due to the conical form of thecowl body the sheet metal of which the cowl body is constructed may becorrugated, thus obtaining greater rigidity of structure.

Within the scoper of the definitions presented in the appended claims,various modiiications and refinements are held in contemplation.

-I claim as my invention:

1. In a ventilatorincluding a cowl having an inlet for communicationwith a Ventilating pas,

sage, an outlet, and means 'for supporting the cowl for rotation on a.vertical axis; said cowl comprising a tubular `rbody of truncatedconical form arranged with the cone vaxis inclined at an angle ofapproximately 8% degrees to a horizontal plane and with the larger endof such conical body directed upward to form the outlet of the cowl, anoutwardly aring peripheral ilange on vthe larger end of said-conicalbody, the plane of said larger end of the so-arranged conical bodyjbeinginclined katan angle of lapproximately 15 ldegrees to a plane normal tothe axis ofthe conical body, whereby the outlet -of said cowl isinclined downward from the top of the cowl'body Aand inward towards saidvertical axis, saidinlet "of the cowl opening from 'below through theside wall of `Asaid Yconical body, and a reentrant tubular portion'extending inward from the smaller end of said truncated conical body toform an ejector tube.

2v. In a ventilator including a cowl having an inlet for communicationwith a Ventilating passagepan outlet, and meansfor supporting thecowlfor rotation on a vertical axis; said cowlv comprising a tubularbody of truncated conical forrriv having an outwardly flaring peripheralilangejon-each of its ends, `said conical body being arranged with itsaxis 'inclined at an angle of less than `30 `degrees to a horizontalplane and with `itslarger flanged end directed upward and formingtheoutlet of the cowl, the plane of said Vlarge; end 'being inclineddownward and inward atan acute'ang1e, said inlet of the cowl comprisinga vertical tube vthat .opens` upwardly through' the sidewall Vof saidconical body, the bottom surface-of the so-arranged conical body beinginclined downward-ly from its smaller end towards'its larger end, withthe lower edge of said ymouth lyingat va point located below the upperedge of said vertical tube, and a tubular portion extending inward fromthe smaller flanged end of said conical body to form an ejector tube. vy Y 'i' lJAMES GUTHRIE.

I3 is shapedl to the proportions

